Banca de QUALIFICAÇÃO: THAIS APARECIDA VITORIANO DANTAS

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : THAIS APARECIDA VITORIANO DANTAS
DATE: 27/06/2024
TIME: 09:00
LOCAL: Virtual/ Google meet
TITLE:

EFFECT OF PLANT DIVERSITY AND FACILITATION ON ARTHROPOD DIVERSITY AND THEIR FUNCTIONS

KEY WORDS:

Biodiversity-ecosystem functioning, facilitation, plant diversity, community structure.

PAGES: 132
BIG AREA: Ciências Biológicas
AREA: Ecologia
SUMMARY:

The global loss of biodiversity has sparked interest in understanding the importance of diversity for the functioning of ecosystems and the stability of ecosystem services. Changes in plant diversity can have reverberating effects on the different trophic levels, affecting the structure and functioning of ecosystems. The relationship between the diversity and functioning of communities can be shaped by the effect of positive interactions, such as complementarity through facilitation, a crucial factor in local diversity patterns. Facilitation refers to positive interactions between different organisms, in which a facilitating organism capable of adapting to situations of greater stress increases the availability of resources and improves local microclimatic conditions, benefiting the establishment and survival of other organisms. In addition, the positive effects of facilitating plant species are also expected to directly or indirectly affect other organisms, such as arthropods and the services they provide within communities. To understand these effects of biodiversity, Biodiversity and Ecosystem Functioning (BEF) experiments have been set up around the world, manipulating tree diversity. In this thesis, we set out to investigate how the richness, composition and facilitation potential of plant communities in a Biodiversity and Ecosystem Functioning experiment affect (i) the soil arthropod community, (ii) the configuration of plant-herbivore interaction networks, and (iii) the ant community and its seed dispersal services. In the first chapter, we tested the effects of tree species richness and facilitation on soil arthropod diversity patterns, considering soil nutrient availability and vegetation structure. Generalized additive models (GAM) showed that tree richness positively affects total arthropod richness, as well as the richness of Hemiptera and Hymenoptera, and negatively the proportion of decomposer abundance. Contrary to what might be expected, facilitation did not affect the structure of the arthropod community. In addition, the availability of nutrients in the soil and the average height of the trees were determining factors in the abundance of arthropods, as well as in the abundance of other taxonomic groups. The second chapter tested how the tree diversity gradient affects the structure of plant-herbivore interaction networks (by controlling plant species composition), and how the structure of plantherbivore insect interaction networks changes over time with community maturity. The results showed that the number of herbivorous insect species associated with the 16 tree species and the number of links they established increased as the community matured. As the plant communities matured, the plant-herbivore network showed less connectivity, 10 less nesting and greater modularity. In addition, tree diversity positively affected connectivity and nesting, but negatively affected network modularity. The third chapter examined the effect of tree diversity, facilitation and the density of trees with extrafloral nectaries on the abundance, richness, functional diversity and phylogenetic diversity of terrestrial ants and on the dispersal, services provided by ants. The generalized linear mixed models (GLMM) showed that tree richness positively affects the abundance, richness, functional diversity and phylogenetic diversity of ants. In addition, tree richness had a strong positive effect on the proportion and distance of dispersed seeds. Contrary to our expectations, facilitation and the number of trees with extrafloral nectaries did not affect terrestrial ants and their functions. With this thesis, we have made a significant contribution to filling important gaps on the effects of plant diversity on the structuring of arthropod communities and the ecosystem services they provide.

COMMITTEE MEMBERS:
Interno - 3060333 - ANDROS TAROUCO GIANUCA
Presidente - 1678202 - CARLOS ROBERTO SORENSEN DUTRA DA FONSECA
Interna - 1914239 - MIRIAM PLAZA PINTO